Your soil was dry so it was maybe an underwatering , if she is burning while the others are not maybe she needs to be feed less than the other because the same feeding can make a plant happy or sad depending on her daily needs.
Now you said your are "guessing budrot" maybe you meant roots rot because you obviously have no buds so you'r safe , you can check the roots but I bet it will not be a problem, must be a feeding / watering issue due to the differents needs of that strain